Aldehyde copolymer



' Patented Nov. 28, 1944 Joseph 0. Patrick, Morrisville, Pa., assignorto Thiokol Corporation, Trenton, N.

ration of Delaware 1., a corpo- No Drawing. Application June '6, 1940,Serial No. 339,076

8 Claims.

This invention relates to the production of polymeric bodies such as maybe obtained by reacting an alkaline polysulphide with certain classes oforganic compounds, and relates more particularly to the formation ofcopolymers.

Alkaline polysulphides can be reacted with organic compounds having twoadjacent carbon atoms to each of which is attached a substituent whichis split 01! during the reaction, e. g., ethylene and propylenedihalides, this reactionbeing described in Patrick Patent 1,890,181.Certain typical polymers of thisclass, while possessing the advantage ofrelatively low cost of DIOdIlC-x tion, have the disadvantage that duringthe curing thereof as such or in admixture with natural rubber, adisagreeablegasis evolved.

The disadvantage mentioned can be avoided and other marked improvementseffected if the space between .the adjacent carbon atoms referred to isopened up and intervening structure placed therein, and polymericproducts are thereby obtained which are substantially polymers oi theunit y a It is an object of the present invention to produce a copolymertree from the disadvantageous gas evolution referred to.

It is a further object to produce a copolymer which combines the markedadvantages of the intervening structure" type of polymer with relativelylow cost.

Other objects and advantages will hereinafter appear.

' 'This invention is based, in part at least, on the discovery of thetheory that the cause of 'the undesirable gas evolution from theadjacent Such polymers may be obtained by reacting an alkalinepolysulphide with an'organic compound having two carbon atoms joined toand separated by intervening structure to each of which carbon atomsthere is attached a substituent which is split oil during the reaction,as well as by other methods, as set forth, for example, in my copendingapplication Serial No. 218.874, tiled July 12, 1988, now,U. S. PatentNo. 2,216,044, issued September '24; 1940. The price paid for thisadvantage is however. in general, an increase in cost of production.

The two types of polymers described, that is; those of the adjacentcarbon atom type and those of the intervening structure type, may be Icopolymerired by various methods as. for example, as set forth in myco-p'ending application Serial No. 267,389,1iled'April 12, 1939, and acorresponding cost advantage obtained; Un-

fortunately, however, certain. typical representatives of thesecopolymers also possess the undesirable property of gas evolutionpreviously mentioned. Theadiacentcarbon atom type of polyme'r andcopolymers made therefrom possess the characteristic structure-c;c.-ss.c.cssand i the undesirable gas evolution appears to be tracebenoted. is'absent from the intervening structure y oipolymer.

able to this characteristic structure which. it will carbon atom type ofpolymer is the presence of the recurring group There is a tendency forthis grouping to under go a cleavage, as shown by the dotted lines, withthe production oi the obnoxious volatile compound HsO-CH:

under reducing conditions which are present whether the compound isheated by itself or compounded with natural or other synthetic rubbersand organic plastics.

The-present invention is an application of the above mentioned discoveryand constitutes one means of avoiding the above mentioned recurringstructure or unit, and byso doing I am enabled to obtain the desiredabsence of undesirable gas evolution in combination with high quality(measured by physical properties) and low cost.

I have good reason to believe that the above theory is correct. Whethercorrect or not, the fact is that the application of said theory hasprovided a solution of the long-standing problem of producing a polymercombining the following qualities (especially after curing):

A. The desired. physical qualities oi resistance to solvents, sunlightand strength and elasticity, etc. I

B. Retention of these qualities. over a wide rangeoitemperature.

0. Freedom .irom undesirable gas evolution when worked. r

D. Low cost. a

The copolymers of this invention. have the eneral formula.

whereciss'singiecsrbonetomc. .cremageing. high tensile sents carbonatoms separated by intervening structure, S is a sulphur atom and m andn are integers the ratio of which signifies the molecular ratios of theradicals (CHzSz to a) and as; a a) The molecular weight isvery high.

aeaoie polysulfide with a. class B compound and a class Acompound.

Such copolymers possess substantially all oi. the

at (E-XI represents carbon atoms joined to and separated the where byintervening structure and X and X represent substituents split offduring the polysulfide reaction, in other words, organic compounds ingeneral having two carbon atoms separated by and able dispersion agentso as to obtain the products joined to intervening structure, each ofsaid carbon atoms having joined thereto substltuents split off duringthe polysulfide reaction. These substances when reacted with an alkalinepolysulfide produce polymers of the unit Class B.Organic compoundshaving in general the formula where R is a radical selected from thegroup consisting of a hydrogen atom, an alkyl radical, an aralkylradical and an aryl radical.

In general the process of the present invention comprises reacting analkaline polysulfide with a substance having the formula to form a.first polymer, reacting an alkaline polysulfide with a compound havingthe formula X- (is-x I Q I u representscarbon atoms Joined to andseparated by intervening structure and X and X' are substituents splitoi! during the reaction, to form a where second polymer and reacting thefirst and second 2. React a metallic alkaline polysulfide with a class Bbody to form a, polymer. Add more of the alkaline polysulfide, ifnecessary, and react therewith a class A compound to form a secondpolymer and combine the two polymers to form acopolymer.

3. Proceed as in 2 but reverse the order, i. e., first react a class Acompound with polysulfide to form a first polymer, then a class Bcompound to form a second polymer and combine the first and secondpolymers to form a copolymer.

4. Proceed as in 2 or 3, but instead of adding additional polysulfide atthe end of the first stage, employ polysulfide generated in thereaction; This may be done by adding a desulphurizing agent to the firstformed polymer which will react therewith and remove labile sulphur andsimultaneously will be converted into polysulfide. Such desulphurizingagent may, for example, be an alkaline monosulfide which as an incidentoi its desulphurizing action is converted into polysulfide. v

All of these reactions are preferably carried out in dispersed conditionin the presence of a suitin the form of aqueous dispersions orlatex-like liquids. The tremendous surface of the polymer in dispersedform facilitates interaction of the individual polymers to formcopolymers.

The alkaline. polysulfides in general may be used, that is, the di, tri,tetra and hexa sulfides of, for example, the alkali or alkaline earthmetals and ammonium (and substituted ammonium) except that where theclass B body reacts with and fixes ammonia (which its true offormaldehyde) a metallic alkaline polysulfide should be used and notammonium polysulfide, for reaction with that body, and the rank or valueof the sulphur integer in the polymer will, in general, correspond tothat in the alkaline polysulfide, and in this way copclymers may bedirectly produced having the general formula (crnsmo;- c osmm Where thealkaline polysulphide is. the an, tetra, penta or hexa sulphide, theformula of the resulting copolymer is such polymers contain sulphur inlabile condition which may be removed by treatment with a desulphurizingagent, thus producing polymers which are wholly or partly in disulphideform as, for example, polymers having the formula- (crnsiim-(c as.

As a; specific illustrative example the following will be given:

Example 1 4.2 mols of Na2S4 in the fdrm of 2100 cc. of a two molarsolution. Add to that 8 grams of sodium hydroxide (NAOH) and '20 gramsof crystall zed magnesium chloride (MgClz.eH2O). The caustic soda andmagnesium chloride are dissolved separately in a little water. Thecaustic and the magnesium chloride solutions are separately addedto thepolysulphide solution in the order named. The polysulphide mixture iscontained in a suitable vessel or flask equipped with means formechanical stirring and with a reflux condenser and thermometer. To thismixture,

while being agitated, are added 2 mols of formaldehyde preferably in theform of a saturated solution of the gas in water containing about 37% byweight of the gas, i. e., about 160 to 165 grams of the aqueousformaldehyde srlution, depending on its exact formaldehyde cont nt. Themixture is then slowly heated to a temperature of 140 F. and 2 mols ofBB dicl ioro diethyl ether are then added at such a rate that about onehour is required for the complete addition of the dichloro diethylether, and the temperature of the mix is controlled in such a way thatthe heat of reaction does not result in temperatures greater than about180 F. during the addition of the dichloro ether.

The reaction mix is then heated slowly to about 210-212 F. for aboutfifteen minutes to complete the reaction. The reaction product, which isin the form of a rather finely divided latex, is then allowed to settleand'the super-- 1 natentliquid is withdrawn, after which the latex canthen be readily dried by treatment on diflferintervening settling anddecanta-- potentially reactive polymer and produces a cured compoundhaving mechanical and solvent resistance to a high degree. Instead-ofzinc oxide (2),

metallic oxides and oxidizing agents in eneral may be employed andinstead of stearic acid (4), acids in general may be used.

Some of th properties of the polymer produced as in Examples 1 and 2 maybe listed as follows:

Tensile strength pounds per sq. in 1,800 Elongation per cent 400Permanent set do 12 The material made in the above manner, whencompounded and cured is not measurably swollen by a weeks immersion inordinary motor gasoline, nor does it impart color to the gasoline, andon a month's exposure to distilled water at a temperature of 120 F. theincrease in weight due to water absorption is less than /100 of 1%. Aunique characteristic of the type of copolymer the preparation of whichwas given in Example 1, is that it may be mixed or combined in anyproportion desired with natural rubber and the resulting compound curedor vulcanized without the formation, even at the high temperature ofvulcanization, of any irritating gas or odor, and the products derivedfrom such a mixture can be used for a y Purpose for which it might bedesirable to use therubber alone, because of the fact that no odorwhatsoever is imparted to the rubber vulcanized by virtue of thisadmixture, although very desirable properties of another type as, j forexample, high resistance to swelling in solvents and high resistance tosunlight and air oxidation are conferred on the rubber mixes.

The copolymer produced as above described has physical properties all ofwhich are at least as good as the polymer made from BB dichloro ethylether by reaction with sodium polysulphide,

and in some respects, particularly in respect of water absorption, thereis an improvement. On

the other hand, the cost of the copolymer is sub- H stantially less thanthat of the polymer made ential rubber rolls or in a suitablemasticator.

Coagulation or separation of the polymer may Example 2 Parts byweight 1. Polymer as above described l--- 100.- 2. Zinc oxide 5. 3.Benzothiazyl disulphide .025 4. Stearic acid v .05 5. Carbon black. 50.

The above components are thoroughly incorporated together as, forexample, by working on rubber differential rolls, and the resultingcompound is then subjected to curing by heating as, for example, in amold. underhydraulically imposed pressure to a temperature correspondingto about 40 pounds of steam or 287 F. for a period of about thirtyminutes.

The curing greatly-enhances and develops the inchoate physicalproperties of the intermediate from the ether derivative alone.

The approximate empirical formula of the above described formula is Thispolymer may be treated with a desulphurizing agent and converted into athe formula p lymer having The desulphurization step will be illustratedas follows:

Example 3 mixture, which should be contained in a vessel fitted withmechanical agitation, is then stirred and is heated to about 200 F. fora period of,

kaline hydroxides or monosulphides, desulphuriz-' ing agents in generalmay be employed including hydrosulphldes, sulphites, hydrosulphites,etc.

The polymer from which the labile sulphur has been removed in the abovemanner possesses, upon curing, improved properties. For example, itstensile strength is higher; its resistance to abrasion is very markedlyincreased; its resistance to freezing is far greater than in the case ofthe untreated polymer. For example, where the untreated polymer wouldbecome still and may even become brittle at a temperature of about 5below zero F., the polymer treated as above described is still flexibleat temperatures as low as 40 below zero F. The treated polymer is alsomuch more resistant .to permanent deformation as a result of pressure,that is to say, its resistance to cold flow is greatly increased as aconsequence of the removal of the labile sulphur.

The polymers obtained as in Examples 1 and 3 "can also be obtained bynumerous variations,

some of which have been described above. For example, the polymer indisulphide form can be obtained by oxidizing a mixture of dimercaptomethane, and BB dimercapto ethyl ether in an alkaline solution employingoxidizing agents in general as, for example, air, oxygen, ozone, sodiumhypochlorite, hydrogen peroxide, alkaline bi chromates, manganates,permangantes and numerous other oxidim'ng agents, and the resultingpolymer in disulphide form can then be treated with elementary sulphur,if it is desired to convert it into a polymer having a higher content ofcombined sulphur. I

Instead of BB dichloro ethyl ether, the present invention employs, ingeneral, organic compounds having two carbon atoms separated by andjoined to intervening structure, said carbon atoms having joinedthereto, respectively, substituents which are (a) capable of being splitofi during the polysulphide reaction, or (b) SH groups. These will beillustrated as follows:

Table I-Intervening linkage characterized by a ether linkageCHa.CHzX.O.CHzX.CHa.

AA disubstituted ethyl ether X-C2H4.0.C2H4-X'.

BB disubstituted ethyl ether X.CH2.0.CH2.X. Dlsubstituted methyl etherX.C;H40.O1H4.O.OH4.X.

Disubstituted ethoxy ethyl ether X.C2H4. s .czrnx'.

Disubstituted thio ethyl ether X.CH2.S .CH:.X.

Dlsubstituted thlo methyl ether X.CHz.O.CHz.C.CH2.OCH2.X.

( JHa Disubstituted 1,3 methoxy, 2, 2 dimethyl propaneX.CH2.CH2.CH2.0.CH2.0.CH2.CH2.CH7.X'.

Disubstituted dipropyl formal xcmcm.o.cH,.o.0H,.oH,.X'.

Disubstituted diethyl formal X.CH2O.CH2.(|3H.O CH1. x, Disubstituteddimethoxy ethane x.omcmoOoomcmxn Disubstituted para dlethoxy benzene X.('JH;O.CH1.CH|.0 CHLX'.

Disubstltllted dimethoxy ethane X.CH:.CH1.CH:. S .CHn.CH:.CH1.X.

Dlsubstltuted dipropyl thio ether pp Disubstltuted dlphenyl etherDisubstituted anisole Disubstituted dibenzyl ether ea. Disubstituteddiphenyl ether I Disubstltuted para propyl dibenzyl etherX.CH;.CH:.S0;.CH,.CHQ.X'

Disllbstituted dlethylsulfone X-CH1-CHLCHI-SOLCHLCHLCHi-X' IDisubstituted dlpropyl sullone CH;.0.CH.CH:.O.CH:.CH;.O.CH .CHg.O.CH:.CH.O.C:H:

l l Disubstituted dimethoxy tetra ethylene glycol cmcmcmojcaomonl 2': x"

AA disubstituted propyl ether CH3.CH:.CH1.Q.CH3.CH7.CH)

1'; l Gamma gamma disubstituted propyl other cmoncmlocmc lmom BBdisubstituted propyl ether CH3.CH.CH=.O.CH.CH:.CH:

Alpha bets disubstltuted propyl ether CHl-CH2-CHLO-CH-CHI-CHI l 1'0Alpha gamma disubstltuted propyl other CH1.CH1.CH,.(|JH.O.CH.CH1.QH,.CH|

Alpha alpha disub stltuted butyl ether CH|.CH:.(|1H.CH.0.CH.CH.CH1.CH:

Beta beta disubstltuted butyl ether cmcrrcm.ornocmcnhcmcn. 1 x

Gamma gamma disub stituted butyl ether (IJH:.CHQ.'CH:.CH:.O.CH:.CH2.CHa-CB: X X

Delta delta dlsubstituted butyl other aseaom Table III-interveningstructure characterized in! saturated hydrocarbon structure aromaticstructure x'cm ' xon Disubstitnted ortho xylene xemcnOcmcmx' ppDhubstituted disthyl benzene m Dillllfihilod mum w-nmuumm mum i 40'Table IV-Iatervening structure characterized i! p Disubstituted dibenzylan Disubstituted nnthnoene Disubstitnted pm ethyl butyl benzenex.CHLCHI-CHOGHI.CHIJJHLEILCHLCHQ Disubstituted para hexyl propyl benzeneIn the above listed compounds X and X represent (a) substituents ingeneral whichare split oil during the poLvsulphide reaction, forexample, halogens, formate, acetate, propionate, b'utyrate, acidtartrate, acid citrate, sitrate, acid sulphate, acid phosphate, etc. and(b) SH for the mercapto reaction wherein the mercapto compounds areoxidized to produce polymers.

For some purposes the alkaline polysulphides of ammonium and substitutedammonium may be employed instead of the metallic polysulphides. Ingeneral it is preferred to use a metallic polysulphide in the reactionwith formaldehyde. However, the formaldehyde may be reacted with ametallic polysulfideto form a first polymer and ammonium or substitutedammonium polysulflde may be reacted with the intervening structurecompound to form a second polymer or vice versa and the two polymersreacted to form a copolymer.

Instead of formaldehyde the present invention employs, in general,organic compounds having the formula Has as already stated, examples ofsuch bodies being as follows:

CH: H =6 Aoetaldohyde a (6B2)- H =0 vuicushomolosem aim-mamas 7 cm tntrio Acroloin OH:

a 1m cram-1m HO-OH as 5-030 Jurlnnl phide and an formula CHOBcnzaldehyde This application is a continuation in part of ,copendingapplication Serial No. 267,389.

I claim:

1. The process which comprises reacting an alkaline metallicpolysulphide with a substance having the formula It nae where R. isselected from the group consisting of a hydrogen atom, an alkyl radical.an aralkyl radical and an aryl radical, to form a first polymer,reacting an alkaline polysulphide with a compound having the formula atax l I u -i ll I n t=o where R is selected from the group consisting ofa hydrogen atom, an alkyl radical, an aralkyi radical and anaryl-radical to form a first polymer and reacting an alkaline metallicpolysulorganiccompound having the int is l l where I J: tl l representscarbon atoms joined to and separated by intervening structure, and X andX are subaseacic stituents split 011 during the reaction, to form asecond polymer and reacting said polymers to form a copolymer.

3. The process which comprises reacting an alkaline metallicpolysulphide with formaldehyde to form a first polymer, reacting analkaline polysulphide wit? an organic compound having two carbon atomsseparated by and joined to intervening structure, said carbon atomshaving joined thereto substituents which are split off during thereaction, to form a second polymer and reacting the first polymer withthe second polymer to form a copolymer.

4. The process which comprises reacting an alkaline metallicpolysulphide with formaldehyde to form a first polymer, reacting analkaline polysulphide with an organic compound having two carbon atomsseparated by and joined to intervening structure, said carbon atomshaving joined thereto substituents which are split ofi' during thereactio to form a second polymer, reacting the first polymer with thesecond polymer to form a copolymer and treating the resulting copolymerwith a desulphurizing agent.

5. The process which comprises reacting an alkaline metallicpolysulphide with formaldehyde and an organic compound having two carbonatoms separated by and joined to intervening structure, said carbonatoms having joined thereto, respectively, substituents which are splitoff during reaction, to form polymers and reacting said polymers to forma copolymer.

-6. Theprocess which comprises reacting an alkaline metallicpolysulphide withformaldehyde and an organic compound having two carbonatoms separated by and joined to intervening structure, said carbonatoms having joined thereto, respectively, substituents which are splitoff during reaction to form polymers and reacting said polymers to forma copolymer and reacting said copolymer with a desulphurizing agent.

7. The process which comprises reactin an alkaline metallic polysulphidewith formaldehyde to make a first polymer, reacting BB dichloro ethylether with an alkaline polysulphide to make a second polymer andreacting the first and second polymers to form a copolymer. r

8. The process which comprises reacting an alkaline metallicpolysulphide with formaldehyde and BB dichloro ethyl ether toformpolymers and reacting said polymers to make a copolymer.

JOSEPH C. PATRICK.

